If the rifles aren't there for photographic effect, I'd move 'em. The top one doesn't look very secure anyway. In any case, peg boards are dandy places to hang tools. Maybe move the peg board and put up the shelving that goes with the mounts you have the peg board on. You can never have too many flat spots that are within easy reach. Gets the scale off the bench when not in use and gives you a handy place for your manuals, brass, dies, etc.
I'd reinforce the center of the bench too. Even thick plywood bends a wee bit. I'm thinking a 2x4 frame screwed to the bottom of the centre, but you're a better builder than I am. Trust me. My bench has a particle board top that broke the very first time I used the press. Had to bolt a square foot of 1/4" mild steel plate on to use it.
You may want to look into another manual as well. Not that the Speer book is bad. It's just that it only gives loads for their bullets. I'd suggest the latest Lyman book. More loads for more bullet makes and powders. It's not cheap though($50Cdn up here) and you don't need it immediately.
If you don't have it already, you'll need a taper crimp die for the .45. Roll crimping doesn't work and a taper crimp will aid feeding.
A speed loading technique calls for two bins. (Buy a few large plastic bins or scrounge a few shoe box sized containers. Preferably with lids.) One with the unprocessed cases on one side of the press, the other for a place for to put processed cases placed on the other side of the press. Do one operation to all your cases then change dies and switch the bins. IE. Size 'em all, then change dies and do the next operation. Use both hands. You may need to move the press about 6" to the left looking at the bench to get enough space for the bin.
The tumbler will go on the floor near power.
You're going to need a bigger bench real soon...